Ch. 7.8 Circulatory System Key Terms
aortic valve
located between the left ventricle and the aorta; allows blood to flow into the aorta and prevents blood from going back into the left ventricle
arrhythmias
abnormal heart rhythms that can be life-threatening
arteries
carries blood away from the heart
blood
flows through the circulatory system, and is often called a tissue because it contains many kinds of cells
Capillaries
connect arteries with venules, the smallest veins
circulatory system
also known as the cardiovascular system, consists of the heart, blood vessels, and blood; transports nutrients and wastes, oxygen and carbon dioxide
Diastole
a long period of rest
Endocardium
smooth layer of cells that lines the inside of the heart and is continuous with the inside of the blood vessels; allows for the smooth flow of blood
Erythrocytes
red blood cells that are produced in red bone marrow at a rate about one million per minute.
Hemoglobin
a complex protein composed of the protein hemoglobin and iron compound called heme
left atrium
receives oxygenated blood from the lungs
left ventricle
receives blood from the left atrium and pumps the blood into the aorta for transport to the body cells
Leukocytes
white blood cells; formed in bone marrow and lymph tissue and usually live about 3-9 days
mitral valve
located between the left atrium and left ventricle; closes when the left ventricle is contracting allowing blood to flow into the aorta
Myocardium
the muscular middle layer of the heart
Pericardium
a double-layered membrane that covers the outside of the heart
Plasma
the fluid that blood is made of; is 90% water
pulmonary valve
located between the right ventricle and the pulmonary artery, a blood vessel that carries blood to the lungs; it closes when the right ventricle has finished contracting
right atrium
receives blood as it returns from the body cells
right ventricle
receives blood from the right atrium and pumps the blood into the pulmonary artery
Septum
muscular wall that separates the heart into the right and left sides; prevents blood from moving between the right and left sides of the heart
Systole
the brief period that follows diastole;; begins when the atria are filling and the ventricles contract
Thrombocytes (platelets)
fragments or pieces of cells because they lack nuclei; formed in bone marrow and live for about 5-9 days. They help your blood clot
tricuspid valve
located between the right atrium and the right ventricle; closes when the right ventricle contracts, allowing for blood to flow to the lungs and preventing blood from going back into the right atrium
Veins
vessels that carry blood toward the heart